Centre of Experimental Medicine of SAS, Dúbravská cesta 9, 84104 Bratislava, Slovakia.
Polymer Research Group, Department of Chemistry, Faculty of Science, University of Tanta, Tanta 31527, Egypt.
Molecules. 2022 Oct 18;27(20):7003. doi: 10.3390/molecules27207003.
The present study aimed at preparing novel free-radical scavenging and water-soluble compounds derived from gelatin. Specifically, gelatin−syringaldehyde, gelatin−anisaldehyde, and gelatin−vanillin were synthesized and thoroughly studied for their physicochemical properties. In particular, the compounds were characterized by UV-Vis spectroscopy, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Notably, as demonstrated by thermogravimetry and differential scanning calorimetry, all three derivatives exhibited higher thermal stability than gelatin itself. Free-radical scavenging activities of the examined compounds were explored by (i) a standard spectrophotometric ABTS assay and (ii) an assay of oxidative degradation of hyaluronic acid monitored by rotational viscometry. We found that gelatin and gelatin−syringaldehyde demonstrated the highest efficacy in scavenging •OH radicals, whereas gelatin−anisaldehyde was the least effective. The efficacy of scavenging alkyloxy- and alkylperoxy-type free radicals via hydrogen-atom-transferring property was in the following order: gelatin > gelatin−vanillin > gelatin−syringaldehyde > gelatin−anisaldehyde. Electron-donor properties determined using the ABTS assay revealed the following order in one-electron reduction of ABTS•+: gelatin > gelatin−anisaldehyde > gelatin−vanillin > gelatin−syringaldehyde.
本研究旨在制备新型的源自明胶的自由基清除和水溶性化合物。具体而言，合成了明胶-对羟基苯甲醛、明胶-香草醛和明胶-茴香醛，并对其理化性质进行了深入研究。特别是，通过紫外可见光谱、傅里叶变换红外光谱和扫描电子显微镜对化合物进行了表征。值得注意的是，热重分析和差示扫描量热法表明，所有三种衍生物的热稳定性均高于明胶本身。通过（i）标准分光光度 ABTS 测定法和（ii）通过旋转粘度计监测透明质酸氧化降解的测定法，研究了所研究化合物的自由基清除活性。我们发现明胶和明胶-对羟基苯甲醛在清除•OH 自由基方面表现出最高的功效，而明胶-茴香醛的功效最低。通过氢原子转移特性清除烷氧基和烷过氧基型自由基的功效依次为：明胶＞明胶-对羟基苯甲醛＞明胶-香草醛＞明胶-茴香醛。使用 ABTS 测定法测定的供电子性能表明，ABTS•+的单电子还原按以下顺序进行：明胶＞明胶-茴香醛＞明胶-香草醛＞明胶-对羟基苯甲醛。
